I wanted a case for my Raspberry PI and I didn't want to spend much or any money. So, like many I turned to LEGOs. I started with the case designed by Biz. While I was building it I noticed a few things I wanted to change. First, there was no easy way to remove the PI once it was in the case. Second, there was also no easy way to see the LEDs on the PI (I now see that there is an updated version of Biz's case that does have a way to see the LEDs). Both of these are very useful whenever debugging is needed. So, like any good maker I did something about it.
Here is the finished prototype. The big changes I made to Biz's case was the addition of a windows for the LEDs and a hinged top that lets you remove the PI.
For fun I then created a better looking design in the LEGO Digital Desinger. I have included my design file (case_lego.lxf) so that anyone can make changes to the design. LEGO used to let you order designs made in the digital designer, but they have discontinued that. To fill that void some users have created a system that lets all the pieces for the set be purchased at once from sellers on bricklink. There is a video here explaining how to get the list of parts into bricklink to be purchased en masse. Basically, you must create an empty wanted list on bricklink, use LDD Manager to get a list of the parts needed for the design, use the id number of the new wanted list to create an xml file in LDD Manager, upload that xml file to bricklink, Use the "By Shop" tab to find a shop that has all the pieces that are in the design. In "By Shop" make sure that the wanted list you created is selected and you are sorting by "Lots (Unique)".
I don't know where I first saw the instructions, but it mentioned using any CD drive/player lense. I used an old 40x CD computer drive (which in itself was fun and enlightening to take apart). When it finally came down to separating the tiny lense from the part holding it, I used wire cutters to cut away most of the plastic, but it turned out that the "glue" holding the lense came off the lense very easily like it was just silly putty.
I recommend this great instructable that uses a
cat toy laser pen lense. If you feel the need to go overboard, your not alone.
You'll need a flashlight because you block most of the light when you are 2mm away from what you are photographing. This is my finger print without a flashlight but I had good lighting above and skin is semi-translucent.
Holding the camera steady at just the right distance is not easy. The CD drive's laser's lense that I used yields such a small depth of field that I taped a column of 0.5cm square pieces of paper to either side of the lense so that I can easily get (and hold) the camera parallel to the surface of flat surfaces I want to photograph. In the pencil on paper photo I simply lifted the end of the camera nearest the lense, but even with such a slight angle to the surface only the middle portion was in focus. Only the top surface of a surface mount resistor is in focus and they are only 0.25mm high!
The last photo below shows millimeter marks on a ruler, so you can compare the objects in the other photos to see how big they are.
We recorded a little radio spot to highlight our involvement in the Science Festival of the Lehigh Valley. It will air on Lehigh Valley Tech Radio.
We will have the following fun activities to share with the Lehigh Valley:
- 3D scanning using a Microsoft Kinect
- 3D printing
- basic soldering classes
- interactive arduino microcontroller projects
[soundcloud url="http://api.soundcloud.com/tracks/42546478" iframe="true" /]
Tom's been working on a dc power supply using parts from his junk box. I really enjoyed the aesthetic of this project. He had a few that he was finishing up at the last open hack. He cut up a can of root beer to create a heat sink, used a board and nails to wire up the connections between the components and wing nuts for good solid connections for both power in and power out.
This project reminded me of an episode of Collin's Lab which looked back to the history of the breadboard a bit. Collin used a real wooden breadboard and nails much like Tom did. The method is basically the same and results in a simple, but custom prototyping space that has a lot of character and can be more permanent than a typical breadboard.
In any case, it is a nice little idea to stick in your back pocket. We played around with the idea of using this project as a workshop project to help teach a few things about electronics. If there is some interest we'll explore that more fully.
Matthew is working on a refurb job for the light on his wife's old coaster bicycle. The original light had two D-cell batteries that had corroded away years ago and lamps that may be hard to replace, but it has a great tactically pleasing switch and body that he hopes to preserve. We discussed options for putting LED lighting in the body of the light. He has a ton of space to work with so I've gone oven to Adafruit and tossed together a wish list of items to use to refurb this. Yeah, it's probably overkill, but it'd be an amazing light.
- USB/DC Lithium Polymer battery charger 5-12V - 3.7/4.2v cells
- Lithium Ion Polymer Battery - 3.7v 1300mAh
I'm not sure what to suggest for the best LEDs to fit the purpose. What do you guys think?